Aspects of the present invention generally relate to compression garments, and particularly to monitoring use of compression garments.
A major concern for immobile patients and like persons are medical conditions that form clots in the blood, such as, deep vein thrombosis (DVT) and peripheral edema. Such patients and persons include those undergoing surgery, anesthesia, extended periods of bed rest, etc. These blood clotting conditions generally occur in the deep veins of the lower extremities and/or pelvis. These veins, such as the iliac, femoral, popliteal and tibial return, deoxygenated blood to the heart. For example, when blood circulation in these veins is retarded due to illness, injury or inactivity, there is a tendency for blood to accumulate or pool. A static pool of blood may lead to the formation of a blood clot. A major risk associated with this condition is interference with cardiovascular circulation. Most seriously, a fragment of the blood clot can break loose and migrate. A pulmonary emboli can form from the fragment potentially blocking a main pulmonary artery, which may be life threatening. The current invention can also be applied to the treatment of other conditions, such as lymphedema.
Conventional vascular compression systems include a compression sleeve or garment fluidly connected to a controller for cyclically inflating the sleeve. The sleeve wraps around a patient's limb and has one or more chambers, or bladders, inflated to provide compressive pulses to the limb, typically starting around the most distal portion of the limb (e.g., the ankle) and progressing sequentially toward the heart. The cyclical inflation of the compression garment enhances blood circulation and decreases the likelihood of DVT. Also, vascular compression systems may be applied to the treatment of other conditions, such as lymphedema.
An important monitoring parameter for compression systems is the venous refilling time (VRT) calculated by the controller, which is the normal time taken for the veins in the limb to distend with blood after compression. Current devices, such as those disclosed in U.S. Pat. No. 6,231,532, detect pressure change (e.g., via a pressure sensor) in the sleeve as a function of the change in girth of the limb to measure VRT. In turn, the controller adjusts the cycle of compressive pulses accordingly based on the calculated VRT.
Patient compliance with a prescribed compression regimen and usage of a compression system is a common problem. Unfortunately, it is nearly impossible in a health service setting for a medical professional to constantly monitor a patient during use of the system. Therefore a need exists for improved compliance monitoring.